Stretchable strap material

ABSTRACT

A stretchable strap material for the shoulder straps of brassieres, slips, nightgowns, swimsuits or other articles of feminine wearing apparel is constituted by a raschel-knitted fabric tape having the desired hand and appearance to match or complement the fabric of the associated wearing apparel and in which longitudinally extending filaments or strands of spandex are laid in, and such raschel-knitted fabric tape is longitudinally folded so that portions thereof define the opposite faces of an outer shell or envelope containing a nonwoven, open randomly reticulate web of thermoplastic synthetic elastic fibers by which confronting portions of the folded tape are bonded together.

O Unite 1 States Patent 1 1 1111 3,873,403

Edelman Mar. 25 1975 STRETCHABLE STRAP MATERIAL 3,153,246 1041964 Silverman 2433s 3,295,529 1 1967 Corri all ct al 128 510 [75] Inventor: I'vmg Edema", Franklm Square 3,552,155 1/1971 Hartu ng 66/192 3,616,148 10/1971 Edelman 128/510 x [73] Assignee: Maid-Rite Novelty Corp., Long I Island City Prtmary ExamtnerHarold Ansher Assistant ExammerHenry F. Epstem [22] F1led: July 2, 9 3 Attorney, Agent, or Firm-Alvin Sinderbrand [2]] Appl. No.: 375,466

[57] ABSTRACT {52] U S Cl 161/76 2/338 66/170 A stretchable strap material for the shoulder straps of /89 l6l/l03 1 brassieres, slips, nightgowns, swimsuits or other arti- 161/156 161/176 cles of feminine wearing apparel is constituted by a {51] lm Cl h 15/00 raschel-knitted fabric tape having the desired hand [58] Fie'ld 192 172 E and appearance to match or complement the fabric of 66/170. 56. 161/103 107 the associated wearing apparel and in which longitudinally extending filaments 0r strands of spandex are laid in, and such raschel-knitted fabric tape is longitu- [56] References Cited dinally folded so that portions thereof define the opposite faces of an outer shell or envelope containing 21 UNITED STATES PATENTS non-woven, open randomly reticulate web of thermo- Nachman v X plastic ynthetic elastic fibers confronting ii portions of the folded tape are bonded together. ac r. 3.078,469 2/1963 Lynam 2/338 5 Claims, 4 Drawing Figures STRETCHABLE STRAP MATERIAL This invention relates generally to shoulder straps for brassieres, slips, nightgowns, swimsuits or other articles of feminine wearing apparel.

It has long been acceptable to be desirable to provide many articles of feminine wearing apparel, such as brassieres, slips, nightgowns, swimsuits and the like, with stretchable shoulder straps for the increased comfort such shoulder straps would afford to the wearer. However, stretchable shoulder straps formed of the commonly available elastic tape detract from the aesthetic appearance of the wearing apparel in that they do not match or harmonize with the fabrics employed for the remainder of the garment, and further are incapable of being dyed to the color of such fabrics. Although attempts have been made to produce stretchable shoulder straps of knitted fabrics containing elastic yarns or filaments, the longitudinal stretching of such straps has been accompanied by lateral narrowing of the strap material with consequent discomfort to the wearer by reason of the reduced area of contact of the straps with the shoulders. Other attempts to provide stretchable strap materials have involved encasing an elastic band or core in a sheath of stretchable fabric which may be transversely pleated, as in US. Pat. No. 1,751,595, or knitted with transverse wales, as in US. Pat. No. 3,078,469. Such strap materials are undesirable in that the thickness is undesirably increased by the elastic band or core and the faces of the strap material do not correspond, in appearance, to the tricot knit fabrics usually employed for feminine undergarments. Further, as in US. Pat. No. 3,295,529, it has been proposed to provide a strap material having a core strip of flexible foam material with a cotton tricot fabric layer adhered to one surface of the foamed core strip and a nylon tricot fabric layer adhered to its opposite surface. This last mentioned strap material is difficult and expensive to produce, and the bonding of the foamed core strip to the outer fabric layers adversely affects the hand and appearance of the latter.

Accordingly, it is an object of this invention to provide stretchable shoulder strap material which avoids the above mentioned disadvantages of materials previously employed for stretchable shoulder straps.

Another object is to provide stretchable shoulder strap material for articles of feminine wearing apparel which may have an outer appearance similar to or harmonizing with the appearance of the fabrics normally employed for such wearing apparel, and which has sufficient elasticity or elastic power to adequately perform the supporting function thereof, as when incorporated in a brassiere or the like.

A further object is to provide stretchable shoulder strap material for articles of feminine wearing apparel, as aforesaid, and in which longitudinal stretching of the strap material is not accompanied by lateral narrowing thereof.

In accordance with an aspect of this invention, the stretchable shoulder strap material is constituted by a raschel-knitted fabric tape having a laid-in structure of spandex filaments or strands extending longitudinally in the raschel-knitted fabric, such tape being longitudinally folded so that portions thereof define the opposite faces of an outer shell or envelope containing a nonwoven, open randomly reticulate web of thermoplastic synthetic elastic fibers by which confronting portions of the folded tape are bonded together.

The above and other objects, features and advantages of the invention will be apparent in the following detailed description of an illustrative embodiment which is to be read in connection with the accompanying drawing, wherein:

FIG. 1 is a fragmentary, enlarged plan view showing the several components of a stretchable shoulder strap material according to this invention prior to the folding and bonding together of such components;

FIG. 2 is a fragmentary plan view of the completed stretchable shoulder strap material as viewed from the side thereof having a longitudinal medial seam therealong;

FIG. 3 is an enlarged, lateral sectional view taken along the line 3-3 on FIG. 2; and

FIG. 4 is a schematic, side elevational view of an apparatus that may be used for producing the stretchable shoulder strap material according to this invention.

Referring to the drawing in detail and initially to FIG. 1 thereof, it will be seen that a shoulder strap material embodying the present invention and generally identified by the reference numeral 10 on FIGS. 2 and 3 is constituted by a tape 11 destined to form the outer shell of the strap material, and a web 12 having width smaller than that of tape 11 and formed of a material capable of bonding together confronting portions of tape 11 when the latter is folded about web 12, as hereinafter described in detail, to form the shell or outer faces of the strap material.

In accordance with this invention, tape II is formed of a raschel-knitted fabric having a laid-in structure of spandex strands or filaments extending longitudinally therein. Since the fabric of tape 11 is raschel-knitted and the longitudinal spandex strands or filaments are merely laid in, rather than being knitted, the tape II can be longitudinally extended against the elastic resis tance of the spandex strands withoutany appreciably lateral narrowing of the tape. In a particular example of this invention, the raschel-knitted tape 11 was formed of 40 denier nylon-6,6 yarn, and the laid-in structure of longitudinal elastic strands or filaments was formed of 420 denier spandex available commercially under the tradename Lycra from E. I. DuPont de Nemours Company, Wilmington, Del.

Further, in accordance with this invention, the web 12 is a non-woven, spun-bonded, open randomly reticulate web of thermoplastic synthetic elastic fibers or filaments, for example, as is available commercially under the trademark Apparelock from the Bostik Division of U.S.M. Corporation, Middleton, Mass. The

elastic, thermoplastic fibers of such web may be, for example, of a linear saturated polyester based material, or of a modified polyester based polyurethane.

In producing the stretchable strap material 10 of FIGS. 2 and 3 from the tape 11 and web 12 of FIG. 1, side portions Ila of tape 11 are folded about fold lines 13 relative to the central portion Ilb on which web 12 is superposed, with the opposite longitudinal edge portions 11c of tape 11 being folded under about fold lines 14. It will be apparent that, upon such folding of tape 11, the raschel-knitted fabric of tape II forms an outer shell or envelope enclosing thermoplastic web 12. with central portion Ilb of tape 11 derining one face of the strap material 10, and with the folded over side portions 11a of tape II coming together to define the other face of the strap material having a longitudinal medial seam extending therealong. The folded under longitudinal edge portions 11c of tape 11 avoid the presence of raw edges of fabric at the medial seam 15. As shown, the folded-under longitudinal edge portions 110 may be of substantially the same width as the folded over side portions 11a of tape 11, so that the thermoplastic web 12 is interposed between central portion 11b and folded-under edge portions 11c which confront each other in the folded condition of tape 11 (FIG. 3).

After tape 11 has been folded about thermoplastic web 12 in the manner described above, the folded assembly is suitably heated so as to render molten or at least plastic the thermoplastic fibers of web 12, whereupon the strap material may be passed between pressure applying rollers or belts which compress together the several fabric layers so as to cause impregnation of the thermoplastic material into the fibers of raschelknitted tape 11. Thereafter, the strap material 10 is suitably cooled so as to set the thermoplastic material employed for bonding together the confronting portions of tape 11 in the folded condition of the latter.

It is an important feature of this invention that, in the completed strap material 10, the thermoplastic material of web 12 does not adversely affect the hand or appearance of either the central portion 11b of the folded side portions 11a of tape 11 which form the outer shell of the strap material. The foregoing is ensured, in the strap material according to this invention, by the fact that the thermoplastic synthetic elastic fibers are in an open, randomly reticulate arrangement in web 12 to avoid any gross or dense impregnation of the knitted fabric of tape 11 with the thermoplastic material. Further, by reason of such arrangement of the elastic fibers in web 12, those fibers when bonding together the confronting portions of tape 11 do not interfere with the longitudinal stretching of the latter and do not induce lateral narrowing of the strap material 10 in response to longitudinal stretching thereof.

Referring now to FIG. 4, it will be seen that an apparatus 100 for producing the shoulder strap material 10 described above with reference to FIGS. 2 and 3 may comprise suitably supported supply rolls 111 and 112 from which tape 11 and web 12, respectively, are simultaneously drawn. Web 12 is superposed centrally on tape 11, as shown in FIG. 1. The assembled tape 11 and web 12 are passed under a guide roller 114 and then through a conventional folding device 115 which continuously operates to fold the longitudinal edge portions 11c of tape 11 onto the adjacent side portions 11a of tape 11. From folding device 115, tape 11 and web 12 pass through a further conventional folding device 116 which continuously operates to fold side portions 11a of tape 11 upwardly and inwardly over web 12, that is, to complete the necessary folding operations. Of course, the folding devices 115 and 116 which are shown separate from each other may be combined in a single conventional folding unit.

After tape 11 has been folded around web 12, the resulting assembly passes continuously through a suitable heating unit 117 which functions to heat the thermoplastic fibers of web 12 to a molten or at least plastic condition. Heating unit 117 may operate on the basis of dielectric or high-frequency electric heating or, as shown, may simply include confronting upper and lower heat conductive blocks 118 and 119 defining a shallow, longitudinally extending groove (not shown) between their confronting surfaces and through which the folded assembly of tape 11 and thermoplastic web 13 is guided during the heating thereof. The conductive or metal blocks 118 and 119 contain conventional electric heating elements 120 and 121 supplied with electric current through suitable thermostatically regulated circuits (not shown).

After web 12 has been rendered molten or at least plastic by the heating thereof in unit 117, the strap material may be passed through the nip 122 between pressure rollers 123 which are suitably driven, as by a motor 124. It will be apparent that the driven rollers 123 constitute at least part of the drive by which tape 11 and web 12 are withdrawn from the respective rolls, and then passed through folding devices 115 and 116 and heating unit 117. The rollers 123 further function to press together the confronting portions of tape 11 with the molten or plastic filaments of web 12 therebetween for ensuring the desired bonding together of such confronting portions of tape 11 and thereby attaining the secure retention of the folded condition of such tape. After passage between rollers 123, the strap material may be guided by a roller 125 and by other similar rollers (not shown) to follow a sinuous path along which the strap material is suitably cooled.

It will be seen that the stretchable shoulder strap material 10 in accordance with this invention may be provided with an attractive or aesthetic appearance by reason of the raschel-knitted fabric outer shell 11 which may be given any desired hand or feel, and, particularly when formed of nylon, may be dyed to any desired color so as to match the fabric and color of the wearing apparel intended to incorporate the strap material. Further, the laid-in structure of spandex strands or filaments, which is relied upon to provide the requisite elastic power for the supporting function of the shoulder strap material, is hidden from view and does not interfere with the characteristic of the raschel-knitted outer shell 11 which permits longitudinal stretching without lateral narrowing.

Although an illustrative embodiment of this invention has been described in detail herein with reference to the accompanying drawing, itis to be understood that the invention is not limited to that precise embodiment, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims:

What is claimed is:

1. A stretchable shoulder strap material for use in articles of feminine wearing apparel consisting of a rasheel-knitted fabric tape having a laid-in structure of spandex strands extending longitudinally therein so that said tape can be longitudinally extended against the elastic resistance of said spandex strands without significant narrowing of the tape, said tape being longi' tudinally folded to define an outer shell having confronting portions, and a non-woven, open randomly reticulate web of thermoplastic synthetic elastic fibers contained by said outer shell and bonding together said confronting portions of the latter without appreciably resisting the longitudinal extension of said tape forming the shell.

2. A stretchable shoulder strap material according to claim 1; in which said raschel-knitted tape is of nylon yarn.

of said tape are folded over said central portion and come together to define the other face of said shell with a longitudinal medial seam along said other face, and folded-under longitudinal edge portions of the tape extend from said seam under said folded over side portions; and in which said web is interposed between, and bonds together said central portion and at least said folded-under longitudinal edge portions of the tape. 

1. A STRETCHABLE SHOULDER STRAP MATERIAL FOR USE IN ARTICLES OF FEMININE WEARING APPAREL CONSISTING OF A RASHEEL-KNITTED FABRIC TAPE HAVING A LAID-IN STRUCTURE OF SPANDEX STRANDS EXTENDING LONGITUDINALLY THEREIN SO THAT SAID TAPE CAN BE LONGITUDINALLY EXTENDED AGAINST THE ELASTIC RESISTANCE OF SAID SPANDEX STRANDS WITHOUT SIGNIFICANT NARROWING OF THE TAPE, SAID TAPE BEING LONGITUDINALLY FOLDED TO DEFINE AN OUTER SHELL HAVING CONFRONTING PORTIONS, AND A NON-WOVEN, OPEN RANDOMLY RETICULATE WEB OF THERMOPLASTIC SYNTHETIC ELASTIC FIBERS CONTAINED BY SAID OUTER SHELL AND BONDING TOGETHER SAID CONFRONTING PORTIONS OF THE LATTER WITHOUT APPRECIABLY RESISTING THE LONGITUDI-NAL EXTENSION OF SAID TAPE FORMING THE SHELL.
 2. A stretchable shoulder strap material according to claim 1; in which said raschel-knitted tape is of nylon yarn.
 3. A stretchable shoulder strap material according to claim 1; in which said fibers of the web are of 100% linear saturated polyester base material.
 4. A stretchable shoulder strap material according to claim 1; in which said fibers of the web are of polyester based polyurethane.
 5. A stretchable shoulder strap material according to claim 1; in which a central portion of said raschel-knitted tape defines one face of said shell, side portions of said tape are folded over said central portion and come together to define the other face of said shell with a longitudinal medial seAm along said other face, and folded-under longitudinal edge portions of the tape extend from said seam under said folded over side portions; and in which said web is interposed between, and bonds together said central portion and at least said folded-under longitudinal edge portions of the tape. 